Ice-making apparatus



NOV. 30, 1954 G MUFFLY 2,695,502

ICE-MAKING APPARATUS Filed Novv. 14) 195o 2 sheets-sheet 1 El IN VENTOR. 95 /e//r Muff@ 92 Ain-e u M MSV ,am

G. MUFFLY ICE-MAKING APPARATUS Nov. 30, 1954 2 Sheets-Sheet 2 Filed NOV.14, 1950 United States Patent flier@ This' invention" isa-further'"development` of the ice making"A apparatus shown inlmy`copending United States application Serial'No.'17`4`,9 44`, 'led July20,` 1950. That patentapplcation'refers in particular to commercial icemaking equipmentand thepresentapplicationto an ice maker ladapted forYuse in a household refrigerator of either the compression ori'absorption type. Itis noted,`

hoWevergthat the "above mentioned application includes features .adapted`for use in household refrigerators and the present application willbeuseful in commerical as.`

wellas'household refrigerators although here illustrated in connection`witlr'a household refrigerator.

Reference .is also madero my United States Patents No." 2,145,775,issuedJanuary 31, 1939; No.v 2,291,826, issued August4, 1942; and No.2,359`,780,"issued October 10, "14944, for.' earlier disclosures of'apparatus lfor lifting ice from -thewater in which it has been formed,for storing the' ice 'above the water 4level and for draining them waterofmeltage from the ice backto the ice maker tankf` Reference is alsomade to my `copending -Urnited` States applications SerialNo.50,10l,`filed September 20,.-` 1948, and Serial No. 109,942, led August12, 1949,` and to my"Canadian patent application fSerialr No. 588,997,flled'lune 13,1949."

In some of the above mentioned earlier Aapplications of'mineglhavedisclosed the use of a waterpumpto circulate water'thr'ough the icemaker-tank or over the surfaces upon whlch ice is being frozen. Y I havealsoshown the method of'oating ice from the tankin which -ithasabeenformed, apparatus for mechanically lifting fthe Aice fromthe` tankand the method of pushingha round diskofice fromthe tank by means of thehead' of Iwater accumulatedba'ck of itwhe'nthe ice` diskblocksvtheover-Alow passage` leading vfrom the tank.

O'ne of the objects ofthe present invention is to elimi-l natethe needffor a water pump withv itsattendant requirementlofa packing gland or avertical drive shaft,`

and still' make vclear ice.

Ariotherlobject is to utilize the elevator which-lifts the ice'from'thewater for the additional purpose of agitat` ing the water `so as tomaintain a constant-flow of water-` overth'e surfaceslof the ice asitforms.

AA further object is to reduce the power requirement lforagitating thewater and lifting the ice.

Anfadditi'onal objeetis` to` provide positive means for i rolling "ice'disks into'the ice storage compartment instead) of 'employing waterflow to float them from `the tankin which they' are formed or to use ahead of water to -pushthem out.

Another'object is to provide means for lifting lthe ice i disksfroml thewater `in` a manner to drain Water from itghemk more completely beforethey drop into the `ice un erft Still another object is to accomplish-the'ice lifting and wateragitation #withfa motor requiringanelectricalinput more nearlylbalancing-the number of B. t. u.s per hourrequ1redto-ma1ntam a Jbutter compartment at the optimum temperaturewhenflocatedtwithn the` food storage compartment of a householdrefrigerator;

A-still further` Objectis to conserve the space vwithin therefrigeratorby a more'compact` arrangement ofparts part ofthezspace for `thedualpurpose =for` storing excesswater in the event and-'by utilizing `aof storing? ice' and thatuall I of the! stored-ice -is accidentally'melted.

-A n.additionali-object-fis to Ycontrol. airl temperature* withinHthemam food compartment `byfm'eansfofa ther-"4 most-atic expansionvalve/mainly responsive to changes` of air temperature and thereby toregulate the proportional Patented Nov; l30, 1954 cooling of the icemaker evaporator an'dthe aircooling Another object isto employ the twoevaporators above mentioned as a secondary systemwhich operates duringidle-periods'` of the compressor to transterheat from cabinet airto the'ice-maker'tank.`

A furtherobject is to causeltheow diverting valve'td" servetheadditional purpose of aiding 1n the detrostlng of' the freezerevaporator and providing for`pre's`sure relief" from "the Vevaporatorbeing defrosted.`

In' the drawings:

Figure Vl is a side elevationof the upper portionof a householdrefrigerator showing the ice-making apparatus partly in section."

Figure 2 is a front vieW-of'Figure 1 showing thesaine apparatus.

Figure l3 is'a horizontal sectional view'of Figure l or Figure 2 takenon the line 3-'-3 thereof, omitting thebelt Figure 4 is a frontelevationof the upperportionofa refrigerator showing a modifiedarrangement `inwhich"" ice is rolled out-of the ice-maker tank andstored ina separate ice bunker.

Figure 5 is a plan view of the apparatusseen'in Fig` ure 4.

Figure 6 is a diagrammatic view showing a refrigeration system suitablefor use in connecuon with the pre1 vious views.

Referring now to Figure l, we see that the refrigerator' cabinet 10encloses an ice-maker tank 12 in-Whichice is frozen bythe methoddisclosed in my previ-ous patents and copending applications andparticularly shown in 'my United States application Serial No. 174,944wherein two disks of ice separately started are causedhto freeze to-lgether to make a thicker disk which is then released 'to float and ispushed from the tank by the head of'water back of it.

ln the present Figure Vl, it will beseen that the ice `disks 14 areAengaged by the vanes 16 which are" attached to or formed integrallywith the belt`18.l This belt vis drivenl by a pulley 20 and runs overtheidler pulley 22' which is located adjacent to the normal operatingwa-l ter level 24 in the tank 12. The belt passes through tle widerupper tank 26 in a space 28 provided in the rear by' of portion/thereofand divided from the main tank 26 means of the walls'tl and 32. The rearend wall 34 the Vice-maker `tank. 12 is joined with 'the rear wallof'the` Y upper tank 26 in the same plane so thatthese rearwalls formone continuous surface which prevents the ice disks 14 from-rolling ofiof the vanes 16 as thebelt 18 car" ries them upwardly to the position ofthe ice disk 14 which is about to roll olf of the beltinto the icebunker" formed' by theupper tank 26.

The pulley 20 is driven at a suitable speed to drive the" belt at suchlinear velocity that the vanes 16' enter and `leave the waterin theice-maker tank 12 withoutobjectional splashing or noise and yet fastenough to produce a substantial circulation of water withinthe icemakertank 12 in `a counter-clockwisedirection as viewed 1n Figure "1. Thiscirculation of water washes air bubbles `from th'eisurfaces of ice disks14 in'process of orma-` tionfand also carries any floating ice disks tothe left as Viewed in Figurer l so they come into engagement with thevanes 1650i the `belt 18 and arefnally liftedby this belt to bedeposited `in the ice bunker 26.` The vanes 16 are preferably solidpaddles and their width'is nearly as great as thatofthe ice maker tank12 so that they produce the maximum movement of water. ice disks to beone inch thick, the width of the vanes 16 will be only slightly lessthan one inch while theirlength- Assuming the measuredlradially from oneof the pulleys as the Vane passes over it is preferably such as toextend from the belt a distance somewhat greater than one-halfthe`diameter of an icedisk.` Since the vertical channel formed t bythe twoside walls 36', the wall 34 and `the beltiis` only slightly wider thanthe thickness of the ice disks, i

they cannot fall off of the vanes 16 travel. The ice disks must,however, as it `passes over the upper fall into the ice bunker 26.

Screens, gratingsror removable sheets 36 Aand 3S' pulley 20 and `theycanV only Separate'the upper'tankZG and the lower tank 12." This pre!during their upward` fall oit of the belti fact that the ice bunker 26is located above the ice-making tank and provided with vertical wallswhich are joined in a water-tight manner to the top of the icemakertank, while the access door 40 is located at the up per front portion ofthe tank, allowing the water-tight front wall of tank 26 to extendupwardly to the opening closed by this door. This provides a water-tightcompartment extending upwardly from the ice-making tank 12 and havingsufficient internal volume to hold more water than would be obtained bymelting the maximum supply of ice that can be stored in the bunker 26.This provides against flooding the refrigerator and the floor of theroom in which it is located in the event of acci dental stoppage such asmight be caused by failure of electrical current or of a vital part ofthe refrigeration system.

In the event that such a failure occurs and operation is re-establishedwhile the upper tank contains the water of meltage, no harm will resultand the first ice disks formed will fall into the water which now llsthe lower portion of the ice bunker. The first of this ice will melt toaid in cooling the water, but as ice begins to accumulate in the bunker,the water level will drop until it will eventually stabilize at thenormal water level 24 within the ice-maker tank 12. Assuming now thatsome of the ice is removed from the bunker and the ice maker continuesto operate, using up some of the water in the tank 12 by converting itinto ice, the water level 24 will fall and with it the float 42 whichcauses the water inlet valve 44 to open and restore the operating levelto the line 24. The same replenishment of water within the tank 12occurs when water is drawn from the faucet 46.

Figure 2 shows a front view of Figure l, including the motor 48 and itsspeed reduction gearing S0 which drives the shaft 52 upon which thedriving pulley 20 is mounted. Due to the light load imposed by thepulleys and belt plus the occasional lifting of an ice disk and the factthat the gearing 50 provides a considerable ratio of speed reduction,the motor 48 can be quite small, preferably consuming not over l wattsand, therefore, it is permissible to locate this motor within therefrigerated space. Some of the waste heat from the motor 48 may beutilized in maintaining the temperature of the butter compartment, aswill later be explained.

In Figure 2, it is seen that the lower left corner of the upper tank 26is rounded and that the bottom of the tank slants downward to the leftside of the ice maker tank 12. This provides for conducting the moisturewhich condenses on the side and bottom of the ice bunker over to a sidewall of the ice-maker tank from which it drops into the pan S4 which,therefore, can be made narrower than would be otherwise required. Thispan is preferably drained to the rear corner of the liner of the foodspace and the water conducted outside of the refrigerated space to bere-evaporated to room atmosphere as disclosed in my copending patentapplication Serial No. 178,498, tiled August 9, 1950.

Referring now to Figure 3, we are looking down on the top of the icebunker 26. The butter compartment 56 is located beside and preferablyseparated from the ice bunker 26. At its front, it is provided with adoor 58 for access and at its rear is provided with a thermostaticallycontrolled shutter 60 which opens in response to a drop of temperaturewithin the butter compartment to allow warm air and radiant heat fromthe motor 48 to enter the butter compartment for the purpose ofmaintaining its temperature. As the butter compartment rises to thedesired temperature, the thermostat 62 moves the shutter in a closingdirection to reduce the heat input to the butter compartment.

The belt 18 and the vanes 16 may be molded or vulcanized together in onepiece using a combination of material or one rubber-like material. It ispreferred that the vanes 16 be flexible or flexibly mounted upon thebelt so as to prevent damage in the event that an extra large disk ofice wedges between a vane and the rear wall 34 of the ice-maker tank inthe position indicated in Figure l by the ice disk 14".

At the top of the rear wall 34 or on the sides 30 of the vertical chute28 a curved shield 64 is provided as an extension of one or two walls toprevent the ice disks from rolling oif from the ends of the vanes 16 asthey approach their top position. The vane then pushes the ice disk offthe top of the pulley with suflicient force to carry it over the wall 32into the ice bunker. In the event that an ice disk should lodge betweenthe belt and the top edge of the wall 32, as indicated by 14 in Figure1, the vane 16 which carried the ice disk up will push the ice disk overthe top of the wall 32 so that it falls into the ice bunker.

In order to make the oat valve 44 readily accessible, I prefer to use atwo-piece cover for the ice-maker tank 12, as shown in Figure l. Theshield 36 fits into the tank 12 and provides an angular wall 66 whichaids in guiding ice toward the elevator. This shield is readilyremovable by merely lifting it out after removing ice from the bunker26. Upon removal of the shield 36 the somewhat similar float cover 38may be removed by sliding it rearwardly, tilting and lifting it outalong with the float 42, its lever arm 68 and its pivot pin 70. kThisprovides access to the valve 44 which is preferably threaded into afitting such as 72 and is readily removable therefrom by the use of asocket wrench. The valve 44 is similar to an automobile tire valve,having a removable core or valve guts. Such valves are well-known astank valves and are commonly provided with 1/s male pipe threads.

In Figure 2, the evaporator 74 is provided with fins 76 and is open tocirculation of air from the food storage space of the refrigerator forthe purpose of cooling the same. The arrows indicate such circulationand the upper one indicates flow of air into the top of the finnedevaporator 74, there being an opening or openings provided in the sheetmetal wall 78 for that purpose. The evaporator 74 may be operatedintermittently during periods when the ice maker evaporator is idle, thetwo evaporators may operate at the same time or they may each operateunder its own control as required to make ice and to maintain thedesired temperature of cabinet air.

It will be obvious that a considerable amount of cooling of cabinet airis obtained by normal gravity circulation of air over the exposedsurfaces of the ice-maker tank 12 and the ice bunker 26 as well as bycontact of the ice-maker evaporator 80 during both its active anddefrosting periods which are controlled to regulate the size of icedisks made. The controls described later herein and illustrated byFigure 6 provide for so proportroning this operation of evaporators 74and S0 that cabinet air temperature is maintained within the desiredllmits and ice production is regulated to maintain the desired supply inthe bunker 26.

The butter compartment 56 is provided with a glass bottom 82 supportedby the two side members 84 which are tied together by two or more crossmembers such as 86. This compartment is closed at the front by the door58 and at the rear abuts the rear liner of the cabinet, so that no rearwall is required.v There is, however, a partial dividing wall 88arranged to separate the butter compartment 56 from the rear compartment90 in which is located the lamp 92. This wall stops short of the top andbottom of the butter compartment so that the heat produced by the lampcauses warm air to ow forwardly over the partition member 88 and toreturn below it. In conventional refrigerators it has been customary toprovide such a lamp with a switch arranged to close when therefrigerator door is opened. Such a switch is located within the housing94 and actuated by the push rod 96 which extends forward so that theswitch is opened whenever the door is closed. In addition to thisswitch, I propose to use a second switch connected in parallel with itand enclosed in the same housing 94. This second switch is of thethermostatic type and arranged to close in response to a drop of airtemperature within the compartment 56 and to re-open in response to arise of this temperature. Such switches have previously been employed toactuate heating elements for the purpose of maintaining the desiredtemperature in a butter compartment of a refrigerator, but

in this case, I propose to use the lamp 92 as a heating element as wellas for the purpose of illumination. In order that the thermostaticswitch need not carry a heavy current, I propose to include a resistancecoil in series with this thermostatic switch and the lamp, so that whenthe lamp is lighted for the purpose of producing heat,

it operatesf at fa. vlowerth-'annormalz voltage; hence 1=pro'- duceslittlelight" but a highpercentageiof heatiin lprop'or-w tionlfftoitheamount lof fligh tf The' A"resistance l*element* f thus. .connected also'provides heat'l'forthe "butter coin-H meanstiof .the iknobL9S'fwhich-carries: a pointer. 10`0flto' indicate itslposition.'

Another. methodsofwsupplying .heatxtotthebutterr cornpartrnent- .isillustrated .in-uFigurcS .-2 and 23,. wherev .the bimetalc thermostat..62 ..actuates.l.. th'efconnectingl rod; .102

to the open positionzasashown' in.. Figure. .2 .when the .bi-w.`

metal.y element'. .62 .drops 1.-to C. the. minimumlitemperatnre desiredwithin` thetbutter. compartment, thus .allowing fheat.. l from'.the...motor..r48 :tokbe .transferred by. .radiation and.

convection :.ftoather. compartment'. 90 .and .'thenceto the butter.compartment: 561 .'by lconvection. The :thermostat all. three be. used.in. thesame model. Normally,. there willbe two sources. of .heatxusedsuch `as the lamp and theY resistance coil, ortheilampuand .theheat..from..thewV motor, hence:therewillzbevonly :one thermostat fem-1`ployed and only.one dialforits adjustment...

`When thel lamp yis-.connected in vseries `.with .the .resistance coil,it is periodically energized even when theudoor of-4 the refrigerator isclosed.: This aids in keepingqthe lampl base, ...its electricalconnections, and th'ethermof" static..switch: dry..` It will. be Inotedthatlthe position-2 of.V thelamp withinva somewhatwarmer compartment'prevents the collection of dew on thelamp and itsbase as .well as -onthe connecting wires. and. the roperating... switch. Theflamps location.:above `the :glass 82 protects. it and avoids the usual interference.with vthe clean-.1

ing of thererigerators interior;`

y It-.is .also within the: scope of..my inventionto.keep. the.lampdnrthe positionshown vand connect. itlonly with. the door-operatedvswitch .so .thatuit operates: in the'1usual:. manner, but .it anditsswitch are enclosed within/:thisv warmer compartment where both. arereadily accessible foriservice and less servicingisfrequiredbecause-rboth:.A In this casel'the. thermostatic switch* ad.` justed -bythe. knob 981 would -be nindependent Vof `thet'lamp circuit and inseries only with theV resistance coil which are .kept dry.

provides all. of` the `heatsfor A the butter compartment. ex-

cept. the incidental' heat from. thewlamp 92, which is.:

produced only while the `.refrigerator door is open.1

.Another arrangement .isto keep.' the lamp-and its. switch 1.independent as above described, eliminating the `knob 98,:-its-.switch-anduthe' resistance coil but-usingthe thermo-v staticallycontrolled shutter wherebygheatfis admitted to .the compartment 90 fromthemotor 48. -This retainsA the. drylocation .of the-.lamp;and itsswitch and provides` the `-additional heat without usefofelectricalcurrent. by. merelyuopeningtthe. louvers .60. when required to main.tain-.the desired .temperature withinathe butter. compartment;

Thefslamp .bulb maybe .removed .by sliding the 4glass .L

82. forward fandwhatever. switch. .or thermostat: 1s used cantbelreadily removed for servicing `along with the sup-5 porting.;.wall.88;:which is preferably made of; thermal angle :instead ofverticallyso-that the round. ice blocks 14 are caused to roll up the.inclinedtrack formed by the wires 110 Jinsteadof being liftedvertically as shown in Figure 1. This elevator delivers theA blocks ofice to :the ice bunker 112 lwhich is `separate from the icemakertankinstead of beirrganupward extension of it as shown in Figures l and 2.The motor .48", whichin" cludes gear reduction `to 4drive the be'lt18"of' Figure 4, `is-locatedoutside" the refrigerated" space'as shoWninFigure 5 instead of being located insideof lthe refrigerated" spaceasshownvin FigureslZ and 3. The/"butter'comf-4 partment56.=isthereforenheated byianelectricalresist ancerfelement tundervthermostatic 1 control as described in connectionlwith "thenlcontrol'.'assembly-f94 A`-V`of.: Figures 2 andi.' 3,1.th`oughrthis:'inotorz zltcould .foptionallywbe located .385 required: .Itooperate a .pump lwhich. produces enough .flow-i partment 56' forthepurposeoflheating"itlifldesiredw Theice'maker"tank 12"\isjoinedataitsV `left endewith tlieice-makerA tank.- The rice-rnalnertankA is.located 3 .15\'..tofffabove LitLas shown .in Figures l and12,.'provision.. is

ing. type driven by aneccentric 122 (Figfj) onftheshaftf' 52;..whichcarriesi the'. pulley. 20 =andldrives` th'e..belt18".2 2(j5..Water..resulting .from ice` .meltage is.. returned .tof-tank. 12'..or 114 by.means. of..the..tube. 124... Theuice-fbunker.-

hinged .attone-halfto two-thirds.ofstheheightof the. e

bunker;r This provides .storage spacetor. Athe '.waterlrre'a.255.2:sulting 'fromicermeltagein the event: .of .current failure"or..-.accidental stoppage of .the refrigerating system... In..

stirredV by thevanes 16 ofthe .belt as previouslyexplainedl. inconnectionwithFigure .1. The beltis-not, however?,f ggg-required to.lift the 4ice disks from .thea .water butmerely. to roll them. up ontheramp formed. by .the..wires.: 110 under guidance ofthe side wires 126.These? wires...

may allbe formedby .one continuouswire which...also.. forms twoVertical. portions 128. andl two angular legs.;130'.`h 1351;.1which.hold the..formed .wire element in. position: and.:

guide the.ice disks upwardlyinto the path. of the vanes.` 16 after theice is released from the walls of .the tank. The two ends of the formedwire are .bent upwardly4i at 1352` to be retained back of the downwardlyextending.. 4012lip134 of the spout-like extension `136 of the. tank114..

Assembly of the wire element to the tank is acomplished by hooking theends 132 back of the lip 134 andtherr., swinging lthefwire membervdownwardly throughthe adjacent corner of the ice-maker tank until thevertical legs %,.;128 snapinto position as shown `in Figure 4f Removal'.isaccomplished by squeezing Ithe two legs` 128 together.` so that thewire will .again pass through.the corner of` the.icemaker tank..

The .float 42 ispivoted at 70 to the inverted. U-shaped member 138 whichts snugly over the end of fthe ice-4 maker tank so that when the float42 falls as a result of a drop of water level in the ice-maker tank thearm 681con tactsthe stem of the valve 4.4 to admit additionalwater...from the supply tube 140.- A wall member 142, which .ispreferablyfremovable, .is provided to preventanypieces of ice fromlloating into the water tank 114. Ice disks are free `to o'at upwardwhenreleased .since `the ice-maker. tank 12 is slightly wider. at itstop than at its bottom as. is thesimilar tank 12 -seen in Figure 2. Thisice mayV :..flo`at directly' into the path of the .vanes 16 of the tbelt 18" or they may be guided into such contact by the angu lar wirelegs 130 or by the .shield 144 which protects the float 42.

In Figures 4 and 5 as .well as in Figures l, 2 and 3,. 65.. the floatingdisks of ice are lifted vfrom/the Water mechanically' rather than beingfloated out as in my .copendM ingapplication, Serial No. 50,101 filedSeptember 20, .1948 or rolled out by a head of water. accumulated backofan... p ice disk asshown in my copending application, Serial No. l17.4,944-led luly 20, 1950. This eliminates.thenecessity forpumpingoverflow water back .to `the ice-maker tank'.v The pulleyr20Which..drives the belt. 18 for llcouldbe driven .at an` extremely slowspeed and still move thebelt rapidly enough to remove 4the ice blocks asfast as they are' released,` but it .is proposed to drive this pulleyata somewhat higher speed so that the vanes 16 will produceV sufcientagitation of the water in the ice-maker tank to wash air bubbles fromthe surfaces of the ice disks as they .30. are'forming and thus insurethe production of clear ice.

Since. Watervis not being. pumped throughrestricted pas-` sages norlifted to produce agitation and thet-motorshaft requiresno.packing:gland,'tlie motor which drivesthe belt-18 or.18.1fcanbeconsiderably smal-lerthan the motor` insidei-theerefrigeratedspaceadjacentrtovthf'butter com-'f the lwater tank1-114 and -theA faucetu 46is connectedI with 5 ".1 this twater `tank YinsteadV .of" being llocatedon one endf of "f thermo'static .hswitch iwhich'ds enclosedwinf ithe=same-hous= ingewith lit, .thusresultingf .inI the. elect of Aan'.anticipating .I thermostat.. l. The thermostatic switch .within T94' 'isladjustable from `the insidefioffthe butter. compartment .by s

cated at the same level as the ice-maker tank insteadly made .fordisposal; of therwater of meltage Thisis donebvs means .of. the'. pump..120.which'-may be `of a reciprocat.

is .provided\with...a water-tight-front .ot which the dooruis Figures 4and' 5,. thewater in the..icemaker .tank .is.

to wash the air bubbles from the iceand tocause the ice to oat out ofthe tank in which it is made.

Figure 6 shows diagrammatically a system suitable for use in connectionwith the previous views and including a freezer evaporator 148 which isemployed to cool a frozen food compartment as is the evaporator 20 of mycopending United States Patent Application Serial No. 74,528 ledFebruary 24, 1949, or evaporator 88 of my copending United States patentapplication Serial No. 178,498 filed August 9, 1950. This evaporatorincludes a header 150 and is selectively cooled under control ofsolenoid valve 152 and thermostatic switch 154 which responds totemperature changes of a bulb located adjacent to evaporator 148.

The solenoid of valve 152 is energized while motorcompressor unitoperates to cool evaporators 80 and 74. During this period refrigerantvapor compressed by the motor-compressor unit 156 is delivered to thecondenser 158 and liquid accumulating therein llows into the receiver159 and thence through the tube -160 to the expansion valve 161 which isof the thermostatic type and has its bulb 162 adjustedly supported, aswill be explained later.

Liquid refrigerant leaves the expansion valve 161 through the tube 163which extends into the tube 164 past the point at which tube 164 isjoined by tube 166. This produces a jet effect which induces ilowthrough the tube 166 in the direction indicated by the arrow. A portionof the liquid refrigerant evaporates in the evaporator 80, seen inprevious figures as part of the ice maker.

Vapor and unevaporated liquid refrigerant flow from 'the evaporator 8i)into the evaporator 74, which is arranged to cool air within therefrigerator cabinet and is preferably provided with extended surface asshown in Figure 2. Refrigerant vapor leaves evaporator 74 through thetube 168 while any unevaporated liquid refrigerant reaching the top ofevaporator 74 flows through the tube 166 into the tube 164 andrecirculates until evaporated. At the time evaporators 88 and 74 areactive the solenoid valve 152 is lifted so that refrigerant vapor flowsfrom the tube 168 into the main suction tube 170, which leads back intothe low pressure casing of the motor-compressor unit 156.

This cycle of operation is under control of the thermostatic switch 172which when closed energizes the motor of the unit 156 and also closesthe circuit through the solenoid of valve 152 which causes the armatureof the solenoid to lift the valve so that tube 168 is open to tube 170.When only the thermostatic switch 154 is closed as a result of a rise oftemperature in the freezer compartment cooled by the evaporator 148, themotor-compressor unit 156 is likewise energized, but there is no Ilow ofcurrent through the solenoid of valve 152, hence the outlet of tube 168is closed and enough pressure will have built up in the evaporators '74and 80 to close the expansion valve 161. Liquid refrigerant thereforeflows from the tube 160 through the branch liquid tube 174 to theexpansion valve 176, which feeds the freezer evaporator 148. Vaporizedrefrigerant leaves the evaporator 148 through the suction tube 178 whichconnects with the header 151B and is now open at the valve 152 for thellow of refrigerant vapor from the tube 178 to the main suction tube 170and thence back to the unit 156.

In the event that thermostatic switch 172 recloses before the switch 154reopens, the cooling effect will shift back to the evaporators 80 and74, due to the energizing of the solenoid and consequent lifting of thevalve member of 152. The main food compartment of the refrigerator isthus cooled and ice is formed until the switch 172 reopens, whereuponcooling of the evaporator 148 continues until the freezer airtemperature falls to the cutout point of the switch 154, whereupon theunit 156 stops.

An additional switch 180 is provided for defrosting of the evaporator148. This may be a double pole, double throw switch, which forconvenience and clarity is here shown as 180A and 188B, with the twoblades or movable members shown in solid lines and their alternativepositions shown by dotted lines. As indicated by solid lines the switch188 is in its normal position which prevails at all times except whenthe heating element 182 is to be energized for thepurpose of defrostingthe freezer evaporator 148.

lt will be seen that when the two blades of the switch 180 aresimultaneously moved to their dotted positions the blade of 180Aconnects one side of the line with one pole` of the solenoid while theblade of 180B connects the f same time the heater 182 causes evaporationof liquid refrigerant in the header of evaporator 148. Such evaporationof refrigerant causes condensation of refrigerant vapor Within the tubesor passages of the evaporator 148 and within the upper portion of theheader 150, thus melting any frost or ice that may have accumulated onthese parts or extended surfaces thereof.

The outlet of tube 178 is stopped by a valve held closed magnetically,hence this valve acts as a pressure relief valve. In the event ofexcessive pressure developing within the evaporator 148 refrigerantvapor is allowed to pass into the tube 17 0 and thence to the lowpressure side of the unit 156, which has ample internal volume toreceive and hold all of the refrigerant vapor that may be passed by thevalve 152 during the defrosting of evaporator 148.

VThe switch may be actuated either manually or automatically, but it ispreferred that at least the termination of the defrosting operation beautomatic, as disclosed in my copending patent application Serial No.178,498 above mentioned, which discloses means for accomplishingautomatic starting as well as stopping of the defrosting operation.

Figure 6 also shows connections for supplying electrical energy to themotor 48 and to the lamp switch and butter compartment heater 94 whichare seen in Figures 2 and 3. lt will be noted that the thermostaticswitch 172 is shown with two bulbs instead of the usual single bulb. Oneof these bulbs is adjustably located adjacent to an ice making area andthe other is located so as to be responsive to changes in the quantityof ice in storage under the additional influence of changes in airtemperature within the refrigerator, as disclosed in my copendingapplication, Serial No. 178,498 and illustrated by bulb positions inFigure 6 thereof. This arrangement causes the switch 172 to regulate theice making cycles to produce ice disks of the desired size and tomaintain the desired quantity of ice in storage, this quantity of icebeing greater when the air temperature of the main food compartment ofthe refrigerator is near its high limit than when the air temperature isnear its low limit.

In addition to this previously disclosed method of control, the presentinvention provides additional means for proportioning the coolingeifects produced by the ice maker evaporator 80 and Vthe cabinet aircooling evaporator 74. The expansion valve 161, being of thethermostatic type, is urged in its closing direction by a reduction oftemperature of the bulb 162. In the event that the bulb 162 is at ahigher-than-normal temperature, the expansion valve 161 maintains ahigher-than-normal operating pressure within the evaporators 80 and 74.It will be noted that the bulb 162 is associated with the outlet ofevaporator 74, but also has a considerable portion of its length exposedto air temperatures above its contact with the tube 168. The bulb isadjustably supported so that more or less of its length can be exposedto cabinet air temperature. An upward adjustment of the bulb may raisethe liquid level within the bulb above the uppermost contact between thebulb and its support or with the tube 168.

This provides for increasing the ilow of liquid refrigerant through theexpansion valve 161 when the air temperature within the refrigerator ishigher than normal. This increased flow of liquid causes evaporator 80to operate at a higher-than-normal evaporating temperature, thus slowingdown the formation of ice. At the same time the greater supply of liquidcauses more of the evaporator 74 to be cooled and this cooling isprolonged due to the slower formation of ice and consequent longerrunning period for each batch of ice frozen.

While the bulb 162 is closely enough associated with the tube 168 toinsure against frost-back, the expansion valve 161 is set at aconsiderably higher superheat than is customary in thermostaticexpansion valves, thus the expansion valve 161 is controlled mainly byair temperature and only in emergency by suction tube temperature toprevent frost-back. Theresult is that evaporator 74 l 9 rtmayhave onlyits klower loops frosted during normalioperation of thef refrigerator;but in -theevent^offrequent door mopenings;` anfr excessively high:`ambient temperature, or the` placing of anfunusualiiamount. of rwarm"food in the f main food icompartment lzoffthe` refrigerator; the evapo-,iis actively cooling theffreezerevaporator 148-, the evapo-l ratorsi 74ands80 are-isolated` from -the balance ofthe ,system bythe valve152,\which closesthevoutlet` of tube 168, and by the expansionvalve-161;.which doesrnot allow -ow.in areverse direction. There will`alwaysibe some liquid refrigerantY trapped-within lthese ltwo,evaporators"` at the time the switch-A 172 `opens. and the solenoid -isthereby des-energized. Thel cross-over tube=-166 allows vaporfrom the`evaporator y74 to flow-,into `.the upper -por- ,tionf the evaporatorSwhere it` will condense dueto `the qzfactthat evaporator 80is 4inintimate thermal contactwith the ice-,maker-,tank12iwhilef theevaporator `74 is notfonly ,.in air,.but is provided with-fina-as seenin Figure 2, so i that it approaches-more closely to` cabinet airtemperature, causing liquid-.refrigerant to evaporate :in-74` `under-the .same pressureat which it condenses in the evaporatorflh* which nowacts as the .condenser of a secondary or ,constant .pressurerefrigeratingsystem, transferring heat from cabinet airto the-,ice-makertank ,12.

Figure` illustratesthemethod of controlling `cabinet air temperature.in,the.main.foodspacepwhich must be.`

` held `abovethefreezingpointandiis preferably -held below '40 F.A..considerablep-part of `the `cooling"effect-required is-,obtained` .by.aircontact with external surface .oftheice,.bunker,.26,the,ice-makerrtank 12` and the icemaker, evaporator80,? but? aavariable amount of addi-t` tional cooling effect.,isrequired to: hold. the ',aintempera- .ture Within the main foodstorage space-.below the desired f, top limit which` may-.be 40, F` .orlower. This Variable cooling effect is. supplied, by;the. evaporator 74.This L evaporator `doessome .cooling 'ofcair each-,time the` ice-H makerevaporator 80..is. cooled. for the purposerof Y,mak-ing 1ce.

Evaporator `80` is. under.;control of thermostatic lswitch 172 which has`two bulbs 1.73 and 173 .connected with Yit, bulb 1173 being locatedrelative to an. ice-making area and bulb "17la"relative,to`,.thefheightzoffthe maximum ice supply lin the storage, compartment,.26.Equivalent loca- ".tions .of the.two bulbs connected with onethermostatic switch are shownat, 44and .138 .in'Figure 6 of -mycopending U`. S, patent lapplication,Serial sNo.` V178,498 `tiled``Augustr9, 1950. "Bulbj173 regulatesice-,making periods Vby stopping thecompressorwhen. a.,givenpiece `of ice has 'grown to the desired size andby starting .the compressor when the icehasmeltedfremfrom the surface onylocated in ,the ice` bunker,takes no. partin the control until the icesupply has accumulated ,toQslightlyabove Vthe Llevel of the bulb, thuscooling bulb,173. andcausingvthe liquid portion of the.volatilechargeofthesthermostatic switch 172 to ,collect in Athisbulb, whichisnowcolder..

`than bulb.'173 associated with the..icemaking area.

Each of these bulbs'. is affected -tofsome `extent byA a rise of cabinetair temperature,.inlthe direction of hastening thelstarting 'ofanice-making cycle andA increasing running timegfwhich etfecttends tocause morecooling` ofcabinet air when the cabinet air-temperature ishigher *than normal, but I have rinthe `present application shownf'additional meansfor control ofcabinet airtemperature- This Acontrol isaccomplished `by further modification of the ice-making cycles and lbyvarying the ;amount :of cool- Vlarger portion of the'evaporatoi 74 willbe actively cooled by the evaporation'of refrigerant.

In order to regulate the removal: of heat from cabinet air I employ thethermostaticexpansion -valve 161, which is responsive to Variations oflow side pressure and also I to variations in temperature fof thebulb162. 'Such bulbs are commonly placed iniheat exchange relationship withthe outlet of an evaporator and the valve is designed to maintainapproximately the desired temperature at` the 4evaporator outlet. It iscommon practice to identify the setting of such` valves -in'terms ofsuperheat of refrig- 1 erant vapor at the pointfof bulb attachment` totheevaporator outlet tube. They are used to insure coolingofsubstantiallythe entire evaporator from'start to `finishy of its activeperiod. In the present caselthe bulb 162 has only a slight contact withthe tube `1158l leading from evaporator 74 but has a considerableportion of its areaexposed to lthe circulation of warm air approachingthetop ofthe tins 76 of evaporator 74.

In addition I makethe valve ^161 responsive to` tem- `peraturechanges-of bulb` 162 at higher temperatures than usual. In Yotherwords,i-the valve 161 is setatY a much higher superheat4 ythan usual.When the'bulb 162 is cooled to say '35- F. theevaporatorit) may beoperating at l` F. withsubstantiallyall oftheliquid refrigerantevaporatingdngthe evaporator 80 and very little of it inl evaporator 74.This condition would be 162 rises. i be mainly responsive -to:temperature lof `the warmer l'ing done bythe'flnn'ed evapo.rator`74. lIt willV be obvious desired size Aand,.duri ng..this longer .periodofoperation a 5:8

ring it within the desired limits.

stated as operating at a superheat` of F. `Ifthe valve really maintaineda 25 superheat vand bulb 162. was increased from a temperature of D to atemperature of the evaporating temperature wouldrise from l0`F. to 15F., thus-slowing down `the formation of ice mand allowing more liquidrefrigerant to'flow 'into-the `evaporator 74.

I may,: however, prefer to design'. the valve 161 so `that the riseoftemperature of bulb 162 increases the ilow of liquid refrigerant so thatevaporator '80 operates at say 20 F. `and a `still'greater proportion ofthe liquid refrigerant flows 'into-evaporator` 74.*'In other words, theexpansionrvalve 161 maywoperate at a diminishing superheat1as=thetemperature of itsbulb ThisY arrangementof `the bulb 162 so asto cabinetair approaching `the 4top ofthe fins76` modifies the cooling lofevaporator -74 'so that only one or two .of lits lower loops may becooled by-evaporation of refrigerant when cabinet air temperature is low(say 35TF.) and substantiallyall of evaporator 74 is cooled Whentheairtemperature rises to say 40" F.

' It will be obvious that under thellatter conditiongthe bulb `162 willbegin to be cooled-bythe tube 168 through Athe air temperature Vmay bequite high,fas infthe case of pulling down a warm cabinet.

In addition to varying the `refrigerated area of evaporator `74 tomaintainthe desired air temperature it will be seen thateach runningperiod` of the connected evaporai tors 74 and 80 will be longer whenthey are operating at .a, higher evaporatingpressure;since this slows`down the formation i of Vice` and the runningperiod ends in response to.the building uptfof'one lof the'ice` disks 14 Vto the maximum sizeestablished bythe `location of thevbulb of thermostat 172 whichAcontacts Athetank 12 adjacent to one of the ice-making areasr thereof.

\ In effect thebulb 162- replaces Y'the usual bulb'of a thermostaticswitchiin the control-of cabinet air temperature. When `cabinet airVtemperature is high` this bulb causes evaporator 74 to be-more fullycooled and to `be cooled for longeroperating periods;` thus pulling theair temperature down to normal for the purpose of hold- The adjustmentof bulb `162 relative `to tube" 168 to` decreasethethermalconductivitybetween' these parts has the effect lof a colder settingofthe ordinary manual adjustment of a thermostat switch which respondsto air temperature within the cabinet. The knob'188, Fig. 2, may bearranged to move bulb "162 for this purpose.

`Another effect obtained by the system illustrated in Fig; 6, as appliedto any of the other figures and particularly to Figs. l, 2 and 3, isthat in the event of a prolonged idle period, such as might be vcaused`by failure of the `source of current,fthefr eserve fcooling effect ofice and rcoldrwater `in-the.Y tank 12 becomes Veffectivefincoolingcabinet air,` `not only fby.qexposed surfacesofrthel tank and of theevaporator 80, but by means of evaporator 74 which acts as a secondaryevaporator during idle periods of the system with evaporator 80 servingas the secondary condenser. This hold-over effect can be greatlyincreased by raising the water level 24 so that at least the lowerportion of the ice stored in ice bunker 26 1s below the water level.While it is true that the water within the tank 12 is normallymaintained between 32 F. and 39.2 F., and is consequently within therange of reverse thermal expansion of water, the 32 water in contactwith the ice will be more dense than the water in the tank 12 when thelatter rises to 40 F. Thus there will be thermal circulation of water inthe event of a prolonged idle period such as might result from currentfailure and this utilizes the stored ice more effectively for thepurpose of cabinet air cooling in an emergency.

The motor 48 may be connected across the line to run continuously or itmay be connected as shown in Figure 6 so that this motor operates duringice freezing periods only. In the latter case it is assumed that thetank 12 will have ample volume above its ice-making areas for releasednieces of ice to float out of contact with such areas or that uponstarting of motor 48 ice will be removed rapidly enough to insureagainst any of the floating pieces of ice being trapped by freezing tothe wall areas which evaporator 8i) is starting to cool.

Figure 6 also shows the wiring to the assembly 94 which includes aheating element and a thermostatic switch for connecting the heatingelement of 94 in series with lamp 92 when the temperature of buttercompartment 56 falls and opening this circuit when the buttercompartment has risen to the desired high limit of temperature. The lamp92 lights under full line voltage as usual when the door-operated switchis closed, this switch being connected to short out the heating elementof 94.

I claim: l

l. In a refrigerator, a refrigerating system for cooling saidrefrigerator, an evaporator included in said system and arranged to coolair within said refrigerator, a portion of said evaporator near itsinlet end being arranged for making ice, a thermostatically controlledexpansion valve connected in said system to control the iiow of liquidrefrigerant to said evaporator, a thermally affected element of saidexpansion valve being exposed to said air and mainly responsive totemperature changes thereof, and control means responsive to theincrease in volume of a body of said ice to control the removal ofrefrigerant vapor from said evaporator, said expansion valve and controlmeans coacting to cause said evaporator to present more cooled area tosaid air and be actively cooled by removal of vapor therefrom for longerperiods of time when said air temperature is higher.

2. In a refrigerator, a refrigerating system including two evaporatorsconnected in series, the first of said evaporators being adapted forproducing sub-freezing temperatures and the second for cooling airwithin said refrigerator, valve means controlling the flow of liquidrefrigerant to the rst of said evaporators, and thermally responsivemeans for controlling the first said means to increase said ow mainly inresponse to a rise of temperature of the cooled air in saidrefrigerator, whereby more or less-liquid refrigerant is caused to enterand evaporate in said second evaporator and said air temperature isthereby held within preselected limits.

3. In a refrigerator, ice-making means, an evaporator associated withsaid ice-making means, a thermostatic expansion valve arranged tocontrol the fiow of liquid refrigerant to said evaporator, a secondevaporator arranged to cool air within said refrigerator and connectedin series to receive liquid refrigerant and the vapor thereof from thefirst said evaporator, said expansion valve having a thermally affectedelement located in position to respond to changes of air temperaturewithin said refrigerator whereby said evaporators are supplied with anincreased flow of liquid refrigerant and caused to operate at highertemperatures when said air temperature is high, and control meansresponsive to ice formation for controlling the operating periods ofsaid pair of evaporators, said operating periods being thereby prolongedwhen the evaporators are operating at higher temperatures and ice istherefore being frozen more slowly, said valve regulating ow so thatonly a part of the second said evaporator is cooled by evaporation ofrefrigerant during periods of low temperature operation and a greaterpart of it being so cooled during periods of higher temperatureoperation, whereby the temperature of said air is maintained withindesired limits.

4. A refrigerating system including two evaporators, one of saidevaporators being arranged to cool a space in which the air temperatureis maintained above 32 F. and the other being adapted for operation at alower temperature, means forming an outlet passage for each of saidevaporators, means forming a main suction passage of said system, valvemeans arranged to connect said outlet passages one at a time with saidmain suction passage, heating means associated with said lowertemperature evaporator to defrost it by causing refrigerant to evaporateand to condense therein, and control means for simultaneously energizingsaid heating means and actuating said valve means to close the outletpassage of said lower temperature evaporator, said valve means being soconstructed and arranged as to act as a pressure relief valve allowingArefrigerant vapor to escape from said lower temperature evaporator intoanother portion of said system when excessive pressures are developed insaid lower temperature evaporator.

5. A refrigerator cabinet including a compartment for the storage offrozen foods and a second compartment adapted to be maintained above 32F., a refrigeration system including two evaporators, one for each ofsaid compartments, means forming a main suction passage of said system,means forming a separate outlet passage for each of the two saidevaporators, valve means arranged to connect said outlet passages one ata time with said main suction passage, and means for defrosting theevaporator which cools said frozen food compartment and simultaneouslyactuating said valve means to close the outlet passage of the last saidevaporator.

6. In a refrigerating system, a pair of evaporators connected in series,a thermostatic expansion valve connected to supply liquid refrigerant tothe first of said evaporators, and a control bulb of said valve locatedadjacent to the second of said evaporators and primarily in heatexchange with cooled air adjacent said evaporator, said bulb being alsoin adjustable heat exchange with the outlet portion of said secondevaporator.

7. A refrigerating system, means for controlling said system to effectcyclic operation of an evaporator thereof whereby a predeterminedquantity of ice is formed during each period of active cooling of saidevaporator, and means responsive to temperature variations of air cooledby said system to modify the operating temperature of said evaporator,thus controlling the temperature of said air by varying the timerequired in forming said predetermined quantity of ice and therebyvarying the lengths of operating periods of said evaporator. Y

8. In a refrigerating system, a pair of evaporators connected in series,the second of said evaporators being ernployed to cool air, athermostatic expansion valve arranged to feed liquid refrigerant to thefirst of said evaporators, a thermo-sensitive element of said expansionvalve located in heat exchange relationship with the second one of saidevaporators and also in heat exchange relationship with circulating airowing toward said second evaporator, and means for adjusting said heatexchange relationships to increase the heat transfer rate of one andreduce the heat transfer rate of the other with reference to saidelement.

9. A refrigerating system including a pair of evaporators connected inseries, the first of said series of evaporators being employed to freezeseparate pieces of ice of which a batch is completed during eachoperating period of said evaporator, control means for regulating saidice freezing periods, means for causing the second of said evaporatorsto be variable as to the area thereof which is cooled by evaporation ofrefrigerant, and control means responsive to temperature changes of airadjacent to said second evaporator for increasing said cooled area inresponse to a rise of temperature of said air.

l0. In a refrigerating system, two evaporators connected in series, athermostatic expansion valve arranged to feed liquid refrigerant to thefirst of said evaporators, and a thermally responsive element of saidvalve so located as to be mainly affected by temperature changes of afluid which recirculates over and is cooled by the second of saidevaporators and secondarily responsive to temperature changes of theoutlet end of said second evaporator.

(References on following page) Number UNITED STATES PATENTS Name DateRezos July 13, 1937 5 Wussow Oct. 18, 1938 Bergdoll Dec. 6, 1938 MuyJan. 31, 1939 Mutfiy Jan. 31, 1939 Kucher Oct. 31, 1939 10 Reilly Apr.16, 1940 Number 14 Name Date Peterson Sept. 17, 1940 Cocanour Nov. 2,1943 Muy May 23, 1944 Pownall Sept. 25, 1945 Copeman Oct. 11, 1949 AskinNov. 8, 1949

